The warning involves Micro-Pace Model 4580 systems, programmable, multi-mode, multi-parameter cardiac pacemakers made by San Diego-based Pace Medica. The Micro-Pace devices also have FDA approval in the U.S.

"The manufacturer has had isolated reports of intermittent sensing issues with the affected product," according to the warning. "Under some circumstances, the affected device would fail to resume nominal sense operation once the programmed rate was lowered or became lower than the patients intrinsic rate."